Insulating material and process for producing the same.



G. W. W. HARDENL ERl-AL'AND PROCESS FOR PRODU APPUCATION HLED- NOV. 15, m3.

CING THE SAME.

INSULATING MAT Patented. Sept. 12,1916.

J GEORGE W; W. HARDER, OF LE ROY, MINNESOTA.

INSULATING MATERIALA ND PROCESS FOR PRODUCING THE SAME.

gg qygg Specification of Letters Patent. Patented dept. I2, ll lltin.

Application filed November 15, 1913. Serial No. 801,213.

T allwhom it may conc n: the insulating, sheet a porous character Be it known that I, GEORGE W. W. HAR- highly desirable for insulating purposes. DEN, a citizen of the United States, residing Partly pulped waste paper is a very cheap at Le Roy, in the county of Mower and source. of'low grade pulp, and this is preferto 1 State of Minnesota, have invented certain ably commingled in water with the straw new and useful Improvements in Insulatjust as it comes from the threshing machine. ing Material and Processes of Producing the I first take old newspapers or other waste Same; and I do hereby declare the followpaper and bring the same to a semi-pulpy ing to be a full, clear, and exact description condition, by rubbing or beating the paper 65 of the invention, such as will enable others in water. I then take the whole raw straw, skilled in the art to which it appertains to preferably a flax straw, on account of its k d use th same, great strength, and mix it with the partly My present invention has for its object to pulped paper, by stirring or beating the provide a fibrous board or sheet which may same in water. By this treatment, the raw we 5 be made at small cost and which has high straw will be intertan led, and the pulp will capacity for insulating heat and cold and be thoroughly commingled therewith, an for deadening'sound. moreover, will adhere to all particlesof the The invention resides both in the product straw. After being thoroughly mixed, the and in the process of producing the same. resultant commingled mass is molded or 3t Paper pulp, or old paper brought to a formed into sheets of the desired thickness pulpy condition, has certain qualities which and is pressed and dried. When thus are ideal for heat and cold insulating mapressed and dried, the pulp paper will form terial, and many eiforts'have been made to an efiicient binder for the raw straw and the utilize old or waste paper for that purpose. raw straw will afford a strong but flexible to All efforts in this direction, however, have reinforcement to the pulp. In this way, the failed because of the impossibility of makgood qualities both of the pulp and of the ing a sufficiently strong or self-sustaining raw straw are utilized and are-made, the and highly porous body or sheet from such one to reinforce the other. Furthermore, pulpy mass. It has been found that if such both the raw straw and the waste paper pulp t pulpy mass was made into a sheet and the are very cheap materials, and in fact, are water pressed out, as in the process of paper the cheapest materials, and at the same making, the product would be a hard board time, the best materials that can be utilized with few air cells and low insulating effor this purpose. The sheet thus formed is ficiency, and if the water was removed from very porous and has a high heat insulating W the sheet by the slow process of evaporation, quality, and furthermore, is flexible, coherinstead of pressure, the product would be cut and strong. much more porous, and hence, a better in- In practice, I have obtained highly satissulating material, but would be so brittle factory results by the use of about one-half and crumbly that it would have little or no pulp and one-half raw straw, but these pro at" 40 commercial value. It isalso found that if portions may, of course, be varied. Inciraw flax straw, for example, were added to dentally, the raw straw will be more or less the pulp, and the whole reduced to a pulpy broken in the process of commingling the condition, practically the same bad results same with the pulp, but all of the particles would follow. of'the whole raw straw remain in the com- 100 By the use of unground stems of raw pleted product, except possibly minute parwhole straw of considerable length, I overticles which incidentally may be washed come the tendency of the pulp to shrink and away, by the water. However, no attempt dry in a hard non-porous condition, and at is made to carry away even these minute the same time, obtain ahighly efficient reinparticles of the raw straw, and the particles 105 forcement to the pulp. Furthermore,I have washed away are so unconsequential that discovered that if pulp is intermixed with such action may be entirelydisregarded. the long unground stems of whole raw straw, The long unground stems of the whole raw such straw will open up and loosen the pulp straw are required, both for the purpose of after the pressure required to remove the giving porosity to the sheet and for giving me water necessarily used in forming the sheet, the same the desired self sustaining an has been removed therefrom, thus giving flexible character. The longer the stems of same.

In these drawings, the

the whole straw, the. better, and they must always be of considerable length, because if ground out up into very short lengths, inf

accompanying drawings wherein *igure 1 is a plan-view showing a sheet or portion of a sheet of the improved material; and Fig. 2 is an edge pulp is indicated by the numeral 1 and the'straw by the numeral 2.

What claim is:

insulating sheet'made of low gradestraw, the pul and'the straw serving as a reinforcement to de up of waste paper pulped at least in part, and long'unground stems of raw wholestraw interminelevation of the gled and felted together, with he pulp serving as a binder to the straw and the straw serving as a reinforcement to the forming air cells in the sheet.

e process of making insulating sheets which consists first, in making low grade pulp, second, in commingling therewith, unground f whole raw straw in water,

the commingled mapulp and first in reducing waste paper condition, second,

In testimony whereof I GEORGE W.

Witnesses:

' BERNICE G. WHEELER,

RRY D. ILGORE.

W. HARDEN. 

